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FOR EXPERT REVIEW PANEL USE ONLY
NOT FOR DISTRIBUTION
2
General safety section needs to be added to the method
Pros/Strengths:
•
Well laid out method with good detail.
•
ISTD added at beginning of sample preparation
•
Instrument and reagents (other than enzyme) are commonly used in the lab
•
No hush sample treatment is involved.
Cons
•
Enzyme effectiveness will be critical for the assay. Need to mention how to ensure the
effectiveness of the enzyme and how it is controlled.
•
More specific information required for sample weight to be used.
•
System suitability: As per SMPR, System Suitability Tests and/or Analytical Quality Control should be
included in the method. An enzyme blank is included but others required, for example, standard
repeatability, slope accuracy, linearity > 0.995
Supporting Data
•
General Comment:
-
Method Optimization: Optimized with enzyme blank subtraction
Method performance requirements:
SMPR:
Applicability: Determination of free and/or total proteinogenic L-α-amino acids and taurine (as shown in
Table 1) in all forms of infant, adult, and/or pediatric formulas (powders, ready-to-feed liquids, and liquid
concentrates).
Analytical range
0.4–2500 mcg/100g RTF
Limit of quantitation (LOQ)
≤ 0.4 mcg/100g RTF
Recovery
90–110%
Repeatability (RSDr)
0.4–5.0
≤ 4%
5.0 – 50
≤ 3%
50 – 2500
≤ 2 %
Reproducibility (RSDR)
0.4–5.0
≤ 6%
5.0 – 50
≤ 4%
50 – 2500
≤ 3 %
Linearity: Minimum of six levels (levels to be agreed upon by SDs) that span the desired working range.
(b) Relative error of back-calculated concentrations determined within the desired working range. (No specifi c
criterion in standard method performance requirement. Recommend calibration errors
to be <5%.) (c) Minimum of three independent experiments. (Independently prepared standards, if feasible.)
Analytical Range:
0.18-300mg/100g of RTF sample (including reconstitute sample)
Linearity:
0.2 – 30 mg/L tryptophan. 8 levels in triplicate with max 1.35 % calibration error
LOQ:
0.18 mg/100g. 0.007 mg/L * 10 = 0.07 mg/L